%% auteur : Péric
-9.5 5.5 setxrange
-1 2.5 setyrange
50 setxunit
18 setfontsize

traceOx
axeOxarrow
/ticklength {10} def
xticks
0 xtick
%[-1 3 7] {xmark} apply
/a {3} def
/b {-0.3} def
(0) 0 b [a dup] dctext
(-2) -2 b [a dup] dctext
(3) 3 b [a dup] dctext
(-7) -7 b [a dup] dctext
(5) -4.5 2 [a dup] cctext
(5) 0.5 2 [a dup] cctext

/arrowscale {2 dup} def
/angleA 130 def
/angleB 50 def
-2 0.5 -7 0.5 (->) pccurve


/angleA 50 def
/angleB 130 def
-2 0.5 3 0.5 (->) pccurve


3 setlinewidth
[xmin 0 -7 0] (-) ligne
[3 0 xmax 0] (-) ligne
([) -6.97 0 [4 dup] cctext
(]) 2.97 0 [4 dup] cctext